1. Field of the Invention
The present invention provides an optical navigation apparatus, an optical navigation method, and a non-transitory computer readable medium thereof. More particularly, the present invention provides an optical navigation apparatus, an optical navigation method, and a non-transitory computer readable medium thereof that are capable of dynamically adjusting a matching block size.
2. Descriptions of the Related Art
Nowadays, computers have become indispensable to the modern person's lifestyle. For most conventional computers, computer mice are used as primary input devices. The computer user often needs to use a mouse to move a cursor displayed on a screen, or even use the mouse to click the desired options, applications, and so on. Therefore, the computer mice have become an important bridge for communication between users and computers. As a result, computer mice adopting various technologies have been developed by mouse manufacturers. Particularly, over recent years, optical navigation apparatuses have become available in the market; an example of which is the Optical Finger Mouse (OFM).
An optical navigation apparatus operates under the following principle: a beam of light is projected by a light source unit onto a reflection surface and images are captured by an image sensing unit. Images that are captured consecutively are compared by a processing unit to determine an offset of the optical navigation apparatus within a time interval. Then, the offset is used to control a cursor displayed on the screen for the purpose of navigation.
For conventional optical navigation apparatuses, movement detection is accomplished by using a predetermined matching block size (e.g., the length and the width of which are both 8 pixels) to compare consecutive images. The predetermined matching block size is invariable and unadjustable. In some cases, the images captured by the image sensing unit may be blurred due to factors, such as a poor working surface or defocusing. In such cases, a smaller predetermined matching block size will lead to an unsatisfactory navigation effect. However, if the predetermined matching block size is enlarged, then more resources of the optical navigation apparatus will be consumed during the comparison process.
Accordingly, an urgent need still exists in the art to provide an optical navigation technology capable of comparing images accurately and efficiently.